<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  
</body>
<script>
  let ws = new WeakSet()

  ws.add({
    name:'test'
  })
  ws.add({
    age:4
  })
  console.log(ws)
  
</script>
</html>